From 1683dcb832c215e294ca1165a78bd7555c5292ec Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Tue, 25 Feb 2020 09:26:22 +0300 Subject: [PATCH] tpm: tpm2_bios_measurements_next should increase position index commit 2bbdf7c302905d581f7dd082d288097a7f29c3a3 upstream. If .next function does not change position index, following .show function will repeat output related to current position index. For /sys/kernel/security/tpm0/binary_bios_measurements: 1) read after lseek beyound end of file generates whole last line. 2) read after lseek to middle of last line generates expected end of last line and unexpected whole last line once again. Cc: stable@vger.kernel.org # 4.19.x Fixes: 46cb04d471b6 ("fs/seq_file.c: simplify seq_file iteration code ...") Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/eventlog/tpm2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c index b9aeda1cbcd72..e741b11575258 100644 --- a/drivers/char/tpm/eventlog/tpm2.c +++ b/drivers/char/tpm/eventlog/tpm2.c @@ -94,6 +94,7 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v, size_t event_size; void *marker; + (*pos)++; event_header = log->bios_event_log; if (v == SEQ_START_TOKEN) { @@ -118,7 +119,6 @@ static void *tpm2_bios_measurements_next(struct seq_file *m, void *v, if (((v + event_size) >= limit) || (event_size == 0)) return NULL; - (*pos)++; return v; } -- 2.39.5